Mobile communication systems provide the subscribers with voice communication services on the move. With the rapid advance of technologies, the mobile communication systems have evolved to support high speed data communication services as well as the standard voice communication services. However, the limited resource and user requirements for higher data rate in the current mobile communication system spurs the evolution to more advanced mobile communication system.
Typically, a terminal having the capability of accessing multiple types of radio access networks (e.g. simultaneously overlaid 2G, 3G, and 4G radio access networks) to connect to a data network selects one of the access networks in a predetermined order. For example, if the access priority is assigned in the order of 4G >3G >2G, the terminal selects the network to attach in descending order of priority. As far as the coverage of the attached access network is maintained, the terminal does not change the access network. That is, if it is located in an overlaid coverage of the 2G, 3G, and 4G access network, the terminal selects 4G access network first to perform attach procedure and maintains the attach to the 4G access network as far as the coverage of the 4G access network is maintained.
However, if a large number of 4G-preferred terminals gather in a specific area selects 4G access network competitively, this makes it difficult for the user to use a service, even the service generates relatively small traffic like such as email and messenger due to the overload situation on the 4G network.
Also, some users can prefer the stable 3G/2G circuit switched (CS) service to the mobile Voice Over Internet Protocol (mVOIP) on the 4G network and other users can use the email and messenger generating small traffic more frequently than the other services.
There is therefore a need of a method capable of selecting an access network for receiving the intended service dynamically according to the user's network preference and type of the service to be provided.